Wang Xin, Niu Zhihao, Li Qingzhong, Scheiner Steve
The Laboratory of Theoretical and Computational Chemistry, School of Chemistry and Chemical Engineering, Yantai University, Yantai 264005, P. R. China.
Department of Chemistry and Biochemistry, Utah State University, Logan, Utah 84322-0300, United States.
Inorg Chem. 2024 Aug 5;63(31):14656-14664. doi: 10.1021/acs.inorgchem.4c02186. Epub 2024 Jul 21.
A systematic theoretical study was conducted on the triel bonds (TrBs) within the TrX···Be(CO) complexes (Tr = B, Al, Ga, In, Tl; X = H, F, Cl, Br, I). The interaction energies of these systems range between 4 and 38 kcal/mol. The TrB weakens as X becomes more electronegative in the B and Al systems, while the opposite pattern of stronger bonds is observed in the In and Tl analogues. The dominant component of the TrB is polarization energy, which arises from charge transfer from Be(CO) to TrX. The source of the density is a confluence of CO π-bonding orbitals at the Be center that resembles a Be lone pair, and which makes the molecular electrostatic potential above the Be somewhat negative. This π-lump is paired with the highly positive π-hole above the Tr, and a large amount of charge is transferred to the empty p orbital of Tr. These factors, when considered in conjunction with large AIM measures, confer on this TrB a certain degree of covalency.
对TrX···Be(CO)配合物（Tr = B、Al、Ga、In、Tl；X = H、F、Cl、Br、I）中的类金属键（TrB）进行了系统的理论研究。这些体系的相互作用能在4至38千卡/摩尔之间。在B和Al体系中，随着X的电负性增强，TrB减弱，而在In和Tl类似物中观察到相反的更强键的模式。TrB的主要成分是极化能，它源于从Be(CO)到TrX的电荷转移。密度的来源是Be中心处CO π键轨道的汇聚，类似于Be孤对电子，这使得Be上方的分子静电势略显负性。这个π团块与Tr上方高度正性的π空穴配对，大量电荷转移到Tr的空p轨道。这些因素，再结合较大的AIM量度，赋予了这种TrB一定程度的共价性。
